Download P310 Trypanosoma brucei PUF RNA binding proteins Katelyn Fenn

P310 Trypanosoma brucei PUF RNA binding proteins
Katelyn Fenn and Keith Matthews
Centre for Immunology, Infection and Evolution, University
of Edinburgh
The transmission of African trypanosomes requires a differentiation from bloodstream form parasites to the tsetse-fly midgut
form, known as the procyclic form. Gene expression in African
trypanosomes is largely regulated post-transcriptionally, due
to the unregulated polycistronic transcription of most genes.
RNA stability and turnover therefore play a major role in gene
regulation, with RNA binding proteins proving to be very important
in these processes. The mechanic actions of the large number
of RNA binding proteins found in the T. brucei genome remain
largely unknown. One of the major cellular changes upon differentiation to the procyclic form is the activation of mitochondrial
genes. These genes include components of the cytochrome
oxidase (COX) complex of the trypanosome respiratory chain,
which is developmentally regulated. Previous studies revealed
that these genes were regulated via signals in the mRNA 3’
untranslated regions (UTRs). In yeast, COX gene expression
is regulated by a PUF RNA binding protein. PUF proteins are
present in most eukaryotic organisms and have been shown to
play a major role in both RNA stability and translational regulation.
Bioinformatic analysis of the T. brucei genome revealed there are
eleven PUF proteins present. To investigate if these proteins are
involved in COX gene regulation, a CAT-COX UTR fusion reporter
system was used. Of the three divergent TbPUF proteins tested,
it appears none of these proteins are involved in COX gene
regulation. Their possible role in other aspects of differentiation is
discussed.